<!DOCTYPE html>
<html>
<head>
    <title>getElementsByClassName() Example</title>
</head>
<body>
    <h1>HTML Ipsum Presents</h1>
               
    <p><strong class="tag">Pellentesque habitant morbi tristique</strong> senectus et netus et malesuada fames ac turpis egestas. Vestibulum tortor quam, feugiat vitae, ultricies eget, tempor sit amet, ante. Donec eu libero sit amet quam egestas semper. <em>Aenean ultricies mi vitae est.</em> Mauris placerat eleifend leo. Quisque sit amet est et sapien ullamcorper pharetra. Vestibulum erat wisi, condimentum sed, <code>commodo vitae</code>, ornare sit amet, wisi. Aenean fermentum, elit eget tincidunt condimentum, eros ipsum rutrum orci, sagittis tempus lacus enim ac dui. <a href="#">Donec non enim</a> in turpis pulvinar facilisis. Ut felis.</p>
    
    <h2>Header Level 2</h2>
               
    <ol>
       <li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li>
       <li class="tag">Aliquam tincidunt mauris eu risus.</li>
    </ol>
    
    <blockquote><p>Lorem ipsum dolor sit amet, <strong>consectetur adipiscing elit</strong>. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est.</p></blockquote>
    
    <h3>Header Level 3</h3>
    
    <ul>
       <li class="tag">Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li>
       <li>Aliquam tincidunt mauris eu risus.</li>
    </ul>


    <script type="text/javascript">
    
    
        if (document.getElementsByClassName){
        
            //highlight all tags with yellow color
            var tags = document.getElementsByClassName("tag");
            for (var i=0, len=tags.length; i < len; i++){
                tags[i].style.backgroundColor = "yellow";
            }
        } else {
            alert("getElementsByClassName() is not supported in this browser.");
        }   


    </script>
</body>
</html>